1. Technical Field
The present disclosure relates to sensors, and particularly, to an angle sensor using magnetism to measure a rotated angle and the angular velocity of a rotary member.
2. Description of Related Art
One way of measuring a rotated angle or the angular velocity of a rotating body is by an angle sensor.
An angle sensor may includes a rotating disc, a light emitter, and a light receiver. The rotating disc defines a number of through holes. The through holes are distributed around the periphery of the rotating disc at a predetermined angle. The light emitter and the light receiver are positioned on opposite sides of the rotating disc, at the periphery of the rotating disc, and aligned with each other. In operation, the rotating disc is driven by a rotary member. When a through hole passes the light emitter, light from the emitter passes through the through hole and impinges on the light receiver. Knowing the radial angle between each through holes and measuring the number of times the light impinges on the light receiver per unit time, the angle sensor can measure the rotated angle and the angular velocity of the rotating disc.
Because the interval between adjacent through holes is fixed, the precision of the current angle sensor cannot be adjusted, and thus the applicability of the angle sensor is limited to one precision measurement.
What is needed, therefore, is an angle sensor which can overcome the above-mentioned problems.